Practical Measurements of Dielectric Constant and Loss for PCB
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Basic PCB Material Electrical and Thermal Properties for Design Introduction
1 Basic PCB material electrical and thermal properties for design Introduction: In order to design PCBs intelligently it becomes important to understand, among other things, the electrical properties of the board material. This brief paper is an attempt to outline these key properties and offer some descriptions of these parameters. Parameters: The basic ( and almost indispensable) parameters for PCB materials are listed below and further described in the treatment that follows. dk, laminate dielectric constant df, dissipation factor Dielectric loss Conductor loss Thermal effects Frequency performance dk: Use the design dk value which is assumed to be more pertinent to design. Determines such things as impedances and the physical dimensions of microstrip circuits. A reasonable accurate practical formula for the effective dielectric constant derived from the dielectric constant of the material is: -1/2 εeff = [ ( εr +1)/2] + [ ( εr -1)/2][1+ (12.h/W)] Here h = thickness of PCB material W = width of the trace εeff = effective dielectric constant εr = dielectric constant of pcb material df: The dissipation factor (df) is a measure of loss-rate of energy of a mode of oscillation in a dissipative system. It is the reciprocal of quality factor Q, which represents the Signal Processing Group Inc., technical memorandum. Website: http://www.signalpro.biz. Signal Processing Gtroup Inc., designs, develops and manufactures analog and wireless ASICs and modules using state of the art semiconductor, PCB and packaging technologies. For a free no obligation quote on your product please send your requirements to us via email at [email protected] or through the Contact item on the website. -
Aperture-Coupled Stripline-To-Waveguide Transitions for Spatial Power Combining
ACES JOURNAL, VOL. 18, NO. 4, NOVEMBER 2003 33 Aperture-Coupled Stripline-to-Waveguide Transitions for Spatial Power Combining Chris W. Hicks∗, Alexander B. Yakovlev#,andMichaelB.Steer+ ∗Naval Air Systems Command, RF Sensors Division 4.5.5, Patuxent River, MD 20670 #Department of Electrical Engineering, The University of Mississippi, University, MS 38677-1848 +Department of Electrical and Computer Engineering, North Carolina State University, Raleigh, NC 27695-7914 Abstract power. However, tubes are bulky, costly, require high operating voltages, and have a short lifetime. As an A full-wave electromagnetic model is developed and alternative, solid-state devices offer several advantages verified for a waveguide transition consisting of slotted such as, lightweight, smaller size, wider bandwidths, rectangular waveguides coupled to a strip line. This and lower operating voltages. These advantages lead waveguide-based structure represents a portion of the to lower cost because systems can be constructed us- planar spatial power combining amplifier array. The ing planar fabrication techniques. However, as the fre- electromagnetic simulator is developed to analyze the quency increases, the output power of solid-state de- stripline-to-slot transitions operating in a waveguide- vices decreases due to their small physical size. There- based environment in the X-band. The simulator is fore, to achieve sizable power levels that compete with based on the method of moments (MoM) discretiza- those generated by vacuum tubes, several solid-state tion of the coupled system of integral equations with devices can be combined in an array. Conventional the piecewise sinusodial testing and basis functions in power combiners are effectively limited in the num- the electric and magnetic surface current density ex- ber of devices that can be combined. -
Agilent Basics of Measuring the Dielectric Properties of Materials
Agilent Basics of Measuring the Dielectric Properties of Materials Application Note Contents Introduction ..............................................................................................3 Dielectric theory .....................................................................................4 Dielectric Constant............................................................................4 Permeability........................................................................................7 Electromagnetic propagation .................................................................8 Dielectric mechanisms ........................................................................10 Orientation (dipolar) polarization ................................................11 Electronic and atomic polarization ..............................................11 Relaxation time ................................................................................12 Debye Relation .................................................................................12 Cole-Cole diagram............................................................................13 Ionic conductivity ............................................................................13 Interfacial or space charge polarization..................................... 14 Measurement Systems .........................................................................15 Network analyzers ..........................................................................15 Impedance analyzers and LCR meters.........................................16 -
Lowpass Lumped-Element Coplanar Waveguide-To- Coplanar Stripline Transitions
LOWPASS LUMPED-ELEMENT COPLANAR WAVEGUIDE-TO- COPLANAR STRIPLINE TRANSITIONS Yo-Shen Lin1 and Chun Hsiung Chen2 1Department of Electrical Engineering, National Central University, Chungli 320, Taiwan, R.O.C. (email: [email protected]) 2Department of Electrical Engineering and Graduate Institute of Communication Engineering, National Taiwan University, Taipei 106, Taiwan, R.O.C. (email: [email protected]) ABSTRACT The lowpass coplanar waveguide-to-coplanar stripline transitions are proposed, using planar lumped-elements to realize the filter prototypes in the transition structures. The proposed transitions are very compact and can provide the combined functions of transition and filter. Simple equivalent-circuit models based on closed-form expressions are also established, from which the characteristics of various lowpass lumped-element transitions are investigated. INTRODUCTION Coplanar waveguide (CPW) and coplanar stripline (CPS) are widely used as building blocks in the design of uniplanar MMIC's [1]. To fully utilize the exclusive features of CPW and CPS, an effective interconnection between them is of crucial importance. This may allow the choice of different uniplanar line-based circuit elements in different parts of a system such that maximum circuit integration and optimal system performance may be accomplished. Various CPW-to-CPS transitions have been developed [2]-[7]. Most of these conventional transitions have bandpass behaviors [2]-[4]. The broadband transition [5] utilizing a slotline open structure has a lowpass frequency response but its insertion loss increases only gradually as the operating frequency increases. The ideally all-pass double-Y junction balun [2], in practice, also features a gradually increasing insertion loss with frequency. -
Application Note: ESR Losses in Ceramic Capacitors by Richard Fiore, Director of RF Applications Engineering American Technical Ceramics
Application Note: ESR Losses In Ceramic Capacitors by Richard Fiore, Director of RF Applications Engineering American Technical Ceramics AMERICAN TECHNICAL CERAMICS ATC North America ATC Europe ATC Asia [email protected] [email protected] [email protected] www.atceramics.com ATC 001-923 Rev. D; 4/07 ESR LOSSES IN CERAMIC CAPACITORS In the world of RF ceramic chip capacitors, Equivalent Series Resistance (ESR) is often considered to be the single most important parameter in selecting the product to fit the application. ESR, typically expressed in milliohms, is the summation of all losses resulting from dielectric (Rsd) and metal elements (Rsm) of the capacitor, (ESR = Rsd+Rsm). Assessing how these losses affect circuit performance is essential when utilizing ceramic capacitors in virtually all RF designs. Advantage of Low Loss RF Capacitors Ceramics capacitors utilized in MRI imaging coils must exhibit Selecting low loss (ultra low ESR) chip capacitors is an important ultra low loss. These capacitors are used in conjunction with an consideration for virtually all RF circuit designs. Some examples of MRI coil in a tuned circuit configuration. Since the signals being the advantages are listed below for several application types. detected by an MRI scanner are extremely small, the losses of the Extended battery life is possible when using low loss capacitors in coil circuit must be kept very low, usually in the order of a few applications such as source bypassing and drain coupling in the milliohms. Excessive ESR losses will degrade the resolution of the final power amplifier stage of a handheld portable transmitter image unless steps are taken to reduce these losses. -
Dielectric Loss
Dielectric Loss - εr is static dielectric constant (result of polarization under dc conditions). Under ac conditions, the dielectric constant is different from the above as energy losses have to be taken into account. - Thermal agitation tries to randomize the dipole orientations. Hence dipole moments cannot react instantaneously to changes in the applied field Æ losses. - The absorption of electrical energy by a dielectric material that is subjected to an alternating electric field is termed dielectric loss. - In general, the dielectric constant εr is a complex number given by where, εr’ is the real part and εr’’ is the imaginary part. Dept of ECE, National University of Singapore Chunxiang Zhu Dielectric Loss - Consider parallel plate capacitor with lossy dielectric - Impedance of the circuit - Thus, admittance (Y=1/Z) given by Dept of ECE, National University of Singapore Chunxiang Zhu Dielectric Loss - The admittance can be written in the form The admittance of the dielectric medium is equivalent to a parallel combination of - Note: compared to parallel an ideal lossless capacitor C’ with a resistance formula. relative permittivity εr’ and a resistance of 1/Gp or conductance Gp. Dept of ECE, National University of Singapore Chunxiang Zhu Dielectric Loss - Input power: - Real part εr’ represents the relative permittivity (static dielectric contribution) in capacitance calculation; imaginary part εr’’ represents the energy loss in dielectric medium. - Loss tangent: defined as represents how lossy the material is for ac signals. Dept of ECE, National University of Singapore Chunxiang Zhu Dielectric Loss The dielectric loss per unit volume: Dept of ECE, National University of Singapore Chunxiang Zhu Dielectric Loss - Note that the power loss is a function of ω, E and tanδ. -
A Comprehensive Guide to Selecting the Right Capacitor for Your Specific Application
CAPACITOR FUNDAMENTALS EBOOK A Comprehensive Guide to Selecting the Right Capacitor for Your Specific Application 2777 Hwy 20 (315) 655-8710 [email protected] Cazenovia, NY 13035 knowlescapacitors.com CAPACITOR FUNDAMENTALS EBOOK TABLE OF CONTENTS Introduction .................................. 2 The Key Principles of Capacitance and How a Basic Capacitor Works .............................. 3 How Capacitors are Most Frequently Used in Electronic Circuits ............................. 6 Factors Affecting Capacitance .................. 9 Defining Dielectric Polarization .................. 11 Dielectric Properties ........................... 15 Characteristics of Ferroelectric Ceramics ......................... 19 Characteristics of Linear Dielectrics .............. 22 Dielectric Classification ......................... 24 Test Parameters and Electrical Properties .......... 27 Industry Test Standards Overview. 32 High Reliability Testing .......................... 34 Visual Standards For Chip Capacitors ............. 37 Chip Attachment and Termination Guidelines ...... 42 Dissipation Factor and Capacitive Reactance ..... 49 Selecting the Right Capacitor for Your Specific Application Needs ............................ 51 1 CAPACITOR FUNDAMENTALS EBOOK INTRODUCTION At Knowles Precision Devices, our expertise in capacitor technology helps developers working on some of the world’s most demanding applications across the medical device, military and aerospace, telecommunications, and automotive industries. Thus, we brought together our top engineers -
The Stripline Circulator Theory and Practice
The Stripline Circulator Theory and Practice By J. HELSZAJN The Stripline Circulator The Stripline Circulator Theory and Practice By J. HELSZAJN Copyright # 2008 by John Wiley & Sons, Inc. All rights reserved Published by John Wiley & Sons, Inc. Published simultaneously in Canada No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning, or otherwise, except as permitted under Section 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the Publisher, or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center, Inc., 222 Rosewood Drive, Danvers, MA 01923, (978) 750-8400, fax (978) 750-4470, or on the web at www.copyright.com. Requests to the Publisher for permission should be addressed to the Permissions Department, John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, (201) 748-6011, fax (201) 748-6008, or online at http:// www.wiley.com/go/permission. Limit of Liability/Disclaimer of Warranty: While the publisher and author have used their best efforts in preparing this book, they make no representations or warranties with respect to the accuracy or completeness of the contents of this book and specifically disclaim any implied warranties of merchantability or fitness for a particular purpose. No warranty may be created or extended by sales representatives or written sales materials. The advice and strategies contained herein may not be suitable for your situation. You should consult with a professional where appropriate. Neither the publisher nor author shall be liable for any loss of profit or any other commercial damages, including but not limited to special, incidental, consequential, or other damages. -
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Lumped-element Sections for Modeling Coupling Between High-Speed Digital and I/O Lines W. Cui, H. Shi, X. Luo, F. Sha*, J.L. Drewniak, T.P. Van Doren and T. Anderson** ElectromagneticCompatibility Laboratory University of Missouri-Rolla Rolla, MCI 65401 * Northern Jiao Tong University EMC ResearchSection Beijing 100044,P.R.China * * HP-EEsof Division Hewlett-PackardCo. SantaRosa, CA 95403 Abstract: Lumped-elementsections are used for modeling designstage to estimateEM1 and minimize the noise coupling coupling betweenhigh-speed digital and I/O lines on printed to I/O lines on the PCB. As digital designs become more circuit boards (PCBs) in this paper. Radiatedelectromagnetic dense, flexibility in trace routing is reduced. Adherence to interference(EMI) is investigatedwhen the I/O line going off simple design maxims for avoiding adjacent segmentsof an the board is driven as an unintentional, but effective antenna. I/O line and a high-speeddigital line becomesmore difficult. Simulated results are compared with measurementsfor A meansfor estimatingEM1 at the design stageis desirableto coupled lines. A suitable number of lumped-elementsections maintainrouting flexibility while minimizing EM1 risk. for modeling is chosen based on the line length and the highestfrequency of interest. The three essentialcomponents for estimating EM1 resulting from coupling to I/O lines are suitable sourceand load models, a coupled transmission-line model, and an EM1 antenna I. INTR~DUC~~N model. Of particular interest at this stage are models for the coupled transmission lines, and the EM1 antenna. Two As the speed of digital designs continues to increase, approaches have been previously pursued for modeling unintentionalradiation from cablesattached to PCBs becomes coupled transmission-lines.One technique is to decouple the problematic.For clock speedsless than 50 MHz, a typical 1 m lines in the frequency domain by modal decomposition [l]. -
LOSSY CAPACITORS 1 Dielectric Loss
Chapter 3—Lossy Capacitors 3–1 LOSSY CAPACITORS 1 Dielectric Loss Capacitors are used for a wide variety of purposes and are made of many different materials in many different styles. For purposes of discussion we will consider three broad types, that is, capacitors made for ac, dc, and pulse applications. The ac case is the most general since ac capacitors will work (or at least survive) in dc and pulse applications, where the reverse may not be true. It is important to consider the losses in ac capacitors. All dielectrics (except vacuum) have two types of losses. One is a conduction loss, representing the flow of actual charge through the dielectric. The other is a dielectric loss due to movement or rotation of the atoms or molecules in an alternating electric field. Dielectric losses in water are the reason for food and drink getting hot in a microwave oven. One way of describing dielectric losses is to consider the permittivity as a complex number, defined as = − j = ||e−jδ (1) where = ac capacitivity = dielectric loss factor δ = dielectric loss angle Capacitance is a complex number C∗ in this definition, becoming the expected real number C as the losses go to zero. That is, we define C∗ = C − jC (2) One reason for defining a complex capacitance is that we can use the complex value in any equation derived for a real capacitance in a sinusoidal application, and get the correct phase shifts and power losses by applying the usual rules of circuit theory. This means that most of our analyses are already done, and we do not need to start over just because we now have a lossy capacitor. -
RF / Microwave PC Board Design and Layout
RF / Microwave PC Board Design and Layout Rick Hartley L-3 Avionics Systems [email protected] 1 RF / Microwave Design - Contents 1) Recommended Reading List 2) Basics 3) Line Types and Impedance 4) Integral Components 5) Layout Techniques / Strategies 6) Power Bus 7) Board Stack-Up 8) Skin Effect and Loss Tangent 9) Shields and Shielding 10) PCB Materials, Fabrication and Assembly 2 RF / Microwave - Reading List PCB Designers – • Transmission Line Design Handbook – Brian C. Wadell (Artech House Publishers) – ISBN 0-89006-436-9 • HF Filter Design and Computer Simulation – Randall W. Rhea (Noble Publishing Corp.) – ISBN 1-884932-25-8 • Partitioning for RF Design – Andy Kowalewski - Printed Circuit Design Magazine, April, 2000. • RF & Microwave Design Techniques for PCBs – Lawrence M. Burns - Proceedings, PCB Design Conference West, 2000. 3 RF / Microwave - Reading List RF Design Engineers – • Microstrip Lines and Slotlines – Gupta, Garg, Bahl and Bhartia. Artech House Publishers (1996) – ISBN 0-89006-766-X • RF Circuit Design – Chris Bowick. Newnes Publishing (1982) – ISBN 0-7506-9946-9 • Introduction to Radio Frequency Design – Wes Hayward. The American Radio Relay League Inc. (1994) – ISBN 0-87259-492-0 • Practical Microwaves – Thomas S. Laverghetta. Prentice Hall, Inc. (1996) – ISBN 0-13-186875-6 4 RF / Microwave Design - Basics ) RF and Microwave Layout encompasses the Design of Analog Based Circuits in the range of Hundreds of Megahertz (MHz) to Many Gigahertz (GHz). ) RF actually in the 500 MHz - 2 GHz Band. (Design Above 100 MHz considered RF.) ) Microwave above 2 GHZ. 5 RF / Microwave Design - Basics ) Unlike Digital, Analog Signals can be at any Voltage and Current Level (Between their Min & Max), at any point in Time. -
A Review of Degradation Behavior and Modeling of Capacitors: Preprint
A Review of Degradation Behavior and Modeling of Capacitors Preprint Anunay Gupta,1 Om Prakash Yadav,1 Douglas DeVoto,2 2 and Joshua Major 1 North Dakota State University 2 National Renewable Energy Laboratory Presented at the American Society of Mechanical Engineers (ASME) 2018 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems (InterPACK 2018) San Francisco, California August 27–30, 2018 NREL is a national laboratory of the U.S. Department of Energy Conference Paper Office of Energy Efficiency & Renewable Energy NREL/CP-5400-71386 Operated by the Alliance for Sustainable Energy, LLC October 2018 This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications. Contract No. DE-AC36-08GO28308 A Review of Degradation Behavior and Modeling of Capacitors Preprint Anunay Gupta,1 Om Prakash Yadav,1 Douglas DeVoto,2 2 and Joshua Major 1 North Dakota State University 2 National Renewable Energy Laboratory Suggested Citation Anunay Gupta, Om Prakash Yadav, Douglas DeVoto, and Joshua Major. 2018. A Review of Degradation Behavior and Modeling of Capacitors: Preprint. Golden, CO: National Renewable Energy Laboratory. NREL/CP-5400-71386. https://www.nrel.gov/docs/fy19osti/71386.pdf. NREL is a national laboratory of the U.S. Department of Energy Conference Paper Office of Energy Efficiency & Renewable Energy NREL/CP-5400-71386 Operated by the Alliance for Sustainable Energy, LLC October 2018 This report is available at no cost from the National Renewable Energy National Renewable Energy Laboratory Laboratory (NREL) at www.nrel.gov/publications. 15013 Denver West Parkway Golden, CO 80401 Contract No.